AKG K-712 Pro

I always had a bit of interest in trying out some better known reference headphones, to see how they stack up to some of my other choices throughout the years, and to see what all the fuss about the sound stage was.

Sound - Really nice. Some frequency range differences were noticeable and overall was clearer than before, but the big difference was the wider sound stage. Going back to other headphones after a few days of listening, I kept thinking on wanting to come back to these because of it.
Running these from a Scarlett 2i2 headphone jack was completely fine, but an amp should be considered if you want slightly better clarity.

Comfort - 5 Stars without glasses, 4 stars with. The headband is really comfy with it's quick adjustment without much thought put into it, and the leather band takes away all parts where hair can get stuck into and pulled out.
The pads were a lot tougher than I expected, but still soft and spacious enough for my ears to be snugly fit, while having plenty of breathing room.
Because of that toughness though, I could still feel some pressure against the frames of my glasses, which got a bit uncomfortable at times. Also, the huge amount of space caused the pads to rub against my glasses and make creaking noises whenever I moved my head around. In comparison, a friends K550 had far softer pads that felt really nice to put on.

Quality - Solidly made, but some of the design choices make me question its long-term durability. Some parts are thin enough that they could easily break when carrying it around in the provided pouch. I'd look into a solid case that's smaller than the box these headphones came in.
The strings on the sides that stretch to fit your head, while convenient, are going to become weaker along the years, which will affect comfort.

Overall though, I'd still give it 5 stars since the comfort and quality issues can be modded around, while the sound itself is really good.

It came in a nice box, well-presented. It's light and feels light on the head. Hardly touches ears. The whole item looks and feels very high-quality, material-wise.
I intend to use these for listening to casual music. I need a relaxed listening experience and this gives me just it. It's amazingly detailed, with a very wide soundstage. If you want to focus on the music, you may do so but for that a Sennheiser HD650 might be a better choice, with relatively non-existent soundstage and in-your-face mids. The K712 feels more in the "front rows", rather than "on the stage"
Also, for immersive gaming (can't speak for competitive) these're amazing.
Don't let the 62 Ohm impedance fool you into thinking you'll be driving these just fine with your typical smartphone. You'll still get a good experience, but you'll most likely benefit a lot from a decent headphone amplifier.
For a casual gamer or listener, these might very well be the endgame.
If you want to get a similar experience, with cut corners in every aspect but mostly the cost,I suggest the fidelio X2HR. But if you have a good amp and can stretch your budget for the K712, you'll not be dissapointed.

I read mixed reviews on this, mostly positive with some negatives. Some said the bass isn't heavy despite the additional 3db in the "low end performance". And granted when compared to my Sennheiser HD650, the bass doesn't seem as pronounced. But this is marketed as a reference headphone so I don't expect this to be the type of headphones for bass heads.

Initially on the first day when I listened to it on my Marantz PM 8006 paired with my Marantz NA6006 as the DAC, it was underwhelming. So I went to sleep and started listening again. It's been almost a week and the details, clarity, airiness and spacious quality to it is something I've come to love, compared to my Sennheisers which has already burned in for sure. I like how the vocals seem to be brought forward while other headphones either has pronounced bass or trebles or just flat sounding which allows everything to just blend together into 1 big musical dish.

Nothing wrong with a flat frequency response, nothing wrong with pronounced bass and trebles. But it's more of a "right time, right tool" kind of situation. Will I listen to an EDM song this with this? Probably not, I would use my Meze Noir or Audio Technica ATH-M50x for it. Pop? Orchestra? Live albums? Yes I would! Also super comfortable for long sessions!

In summary, would I recommend this? Yes! Especially to own a piece of history! Would I say it has flaws? Yes, cause nothing is perfect, but again, I think you'll have to consider the type of music you're listening. I would use this for pop, orchestras and songs where I want to pay attention to the lyrics. But I won't use this for songs that are bass dependent as it'll probably won't suffice. Looking forward to getting a cable approx 30cm/1ft long and 3D print a holder to put my Fiio BTR5 to use it as a bluetooth headphone around the house. It's light feeling to do that and sometimes, you just don't want cable getting in your way, even with the included cable being long as it is

AKG headphones have been lifelong companions to me. STarted out with a K-171 which served me well for 12 years, then moved on to K-240 MKII, which has been unbeaten so far... until now.

Unfortunately the first pair arrived with a manufacturing fault, but Thomann did a stellar job replacing the unit with a good one. Doesn't score good points for quality control on AKG's side, but I guess these things happen (hence 4 stars for quality instead of 5).

Build quality: flawless, as usual with their "pro" line. Ear pads are similar to other AKG cans, except under the velour you have memory foam that provides a better low-frequency insulation (without increased pressure on your head). You get two cables, an orange straight one, and the more practical coiled cable, both are of extremely good quality (I have one from my old K-171 that still works after rolling the office chair over it a couple of times).

Comfort: awesome. Light, but sits on its place well, even if you move around with it quite a lot.

Sound: these headphones need to be broken in (they start to sound better after 50 hours, really good after 100 hours of use). After that they really start to sound great. Spacious, incredible 3-dimensional sound stage, with fantastic separation between instruments. Since they are open, don't expect the kind of bass build-up / booming bass that is typical to semi-open and closed models, but in return you get a much more "effortless" sounding, precise low end.

All-in-all: I am using my AKG K-712 PRO for mastering and mixing jobs with great results.